Methods incorporating diffuse reflectance spectroscopy (DRS), into standard ablation catheters suffer from instability of collection of optical spectra due to motion of the catheter and inconsistent contact pressure. Furthermore, DRS deployed with a small offset between illuminating and collecting fibers have only small penetration depths. Standard ablation catheters cannot achieve a sufficient spatial offset between illuminating and receiving optic fibers due to the limited length of the distal tip of the ablation catheter that is in contact with the heart during ablation and therefore cannot exploit spatial offset to achieve greater penetration depths.
In ablation of cardiac tissue, the “first hit” is the most important. Therefore applying energy in the correct dosage and for the correct duration is critical to achieving transmurality. Insufficient energy and duration will lead to ineffective lesions which result in local tissue swelling and edema which will prevent further effective completion of the lesion at the same location. Checking for lesion characteristics after the first ablation is therefore ineffective. On the other hand, applying too much energy for too long can lead to collateral damage like coagulum formation and damage to surrounding structures. What is therefore needed is a device and method to allow monitoring of the ablation lesion as it is being formed and to adjust power and duration settings according to predetermined optimum levels for achieving transmurality and for preventing collateral damage.